Reference:

Javier Esparza, Michael Luttenberger, and Maximilian Schlund. A brief history of strahler numbers. In Language and Automata Theory and Applications - 8th International Conference, LATA 2014, Madrid, Spain, March 10-14, 2014. Proceedings, pages 1–13, 2014.

Suggested BibTeX entry:

@inproceedings{DBLP:conflataEsparzaLS14,
    author = {Javier Esparza and Michael Luttenberger and Maximilian Schlund},
    booktitle = {Language and Automata Theory and Applications - 8th International Conference, {LATA} 2014, Madrid, Spain, March 10-14, 2014. Proceedings},
    pages = {1--13},
    title = {A Brief History of Strahler Numbers},
    year = {2014}
}